Simple Calculator to Convert Decimal to Hexadecimal

[napster161]

1st Question:
Correction: BINARY to HEXADECIMAL
I have write some simple code for this matter

public class DecimalToHexadecimal{
  public static void main(String[] args) throws IOException{  
    BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("Enter the decimal value:");
    String hex = bf.readLine();
    int i = Integer.parseInt(hex);
    String hex1 = Integer.toHexString(i);
    System.out.println("Hexa decimal: " + hex1);
  }
}

But i already got some error there,anyone??

2nd Question:
The different between java.util, java.lang, java.io

Thanks in advance :)

[Curtis Rutland]

This is obviously a homework problem. I suggest you read our Posting Guidelines on Homework Questions.

So, all I can suggest for your second question is to consult your textbook or google.

For your first question, what error? Without detail, we cannot help.